As I mentioned earlier, my laptop now works. Credit goes to my dad for finding the answer to the problem and I feel compelled to explain it here as apparently the answer is very difficult to find.
At the moment I don’t know where the solution is, if I did then I would link to it (if you know, let me know).

So, enough beating around the bush, to the explanation.

First, the problem:
When pressing the power button on the laptop, the power light comes on for about two seconds, then the hard disk light flashes and the power light goes off. No booting, no whir of fans, nothing.

The solution:
You need new RAM, the old stuff has packed up. Quite a simple solution really.

My excuse for not finding this out is that before my laptop ‘died’ it was having hard drive problems, so of course I assumed that was the problem when it stopped working. The fact that it didn’t even get into the BIOS and no longer displayed the helpful ‘Boot device not found’ message should really have alerted me to further possibilities.

Truth be told I was kinda looking for a good excuse to build a spangly new machine anyway. Now I’ve got the best of both worlds!!
Bonanza!